Which of the following statements correctly describes the resonance structures of the carbonate ion, CO_3^{2-}?

• A. There are three equivalent resonance structures, each with one double bond and two single bonds between carbon and oxygen.
• B. There is only one resonance structure, with all bonds between carbon and oxygen being single bonds.
• C. There are three resonance structures, each with two double bonds and one single bond between carbon and oxygen.
• D. There are two resonance structures, each with two double bonds and one single bond between carbon and oxygen.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the concept of resonance structures. Resonance structures are different Lewis structures for the same molecule that show the delocalization of electrons. They differ only in the placement of electrons, not the arrangement of atoms.
2. Step 2: Draw the Lewis structure of the carbonate ion, CO_3^{2-}. Carbon is the central atom bonded to three oxygen atoms. The ion carries a -2 charge, which affects the total number of valence electrons.
3. Step 3: Determine the possible resonance structures by distributing the double bonds between carbon and oxygen. Since carbon can form a double bond with only one oxygen at a time, the double bond can be placed with any one of the three oxygens, while the other two oxygens have single bonds.
4. Step 4: Recognize that there are three resonance structures, each with one double bond and two single bonds between carbon and oxygen. These structures are equivalent because the double bond can be on any of the three oxygens, and the negative charges are delocalized.
5. Step 5: Conclude that the correct description is that there are three equivalent resonance structures, each with one double bond and two single bonds between carbon and oxygen, reflecting the delocalized nature of the bonding in the carbonate ion.